Clutch control



Nov. 2, 1937. R. H. wHlsLER 2,098,076

CLUTCH CONTROL Ofiginal Filed 0G13. 13, 1934 4 Sheets sheet l Nov. 2,1937. R. H. wHlsLER CLUTCH CONTROL Original Filed Oct. 13, 1934 4SheeiS-Sheet 2 l m5 NWXNN x In Ver) or.-

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CLUTCH CONTROL l Original Filed Oct. 13, 1934 4 Sheets-Sheet 3 yHiya/nig CLUTCH CONTROL Oiginal Filed Ooi. l5, 1934 4 Sheets-Sheet 4IN1/n for:

Patented Nov. 2, 1937 UNITED STATES PATENT OFFICE CLUTCH Ralph H.Whisler, St.

CONTROL Clair Shores, Mich., as-

signor, by mesne assignments, to Carter Carburetor Corporation, St.Louis, M0., a corporation of Delaware 8 Claims.

This invention relates generally to carburetor and vacuum clutch controlmechanism and has for its principal objects to provide improved meansfor controlling the deceleration of the engine when the main carburetorthrottle valve is closed and to provide in conjunction therewith, animproved and effective means for controlling the operation of a vacuumactuated clutch by properly timing the engagement and disengage- 13 mentof the same in relation to the engine acceleratlon and deceleration sothat improved automatic clutch operation will be secured. 'I'he presentapplication is a division of a copending zligplication, Serial No.748,197, filed October 13,

Considered from one important aspect, the invention is especiallyadaptable to motor vehicles of the type having a relatively highpower-toweight ratio. Such vehicles have a desirably high rate ofacceleration when the throttle valve is opened, but, on the other hand,when the throttle valve is completely closed, are often decelerated at arate which, under many driving conditions, is undesirably rapid. Inorder to secure smooth operation, the final shutting olf of the power ofthe engine by the closing of its throttle valve should conform as nearlyas possible to the natural loss of momentum of the vehicle; otherwisethe progress of the car is likely to be characterized by suddendecelerations which are very disagreeable to the passengers,particularly if the operator suddenly removes his foot from theaccelerator pedal. In cars equipped with vacuum operated automaticclutches, it is desirable to prevent a too sudden nal closing of thethrottle and consequent rapid engine deceleration. since under suchconditions an undes irable delay in the disengagement of lthe clutchoften occurs.

An object of the present invention is to provide a delayed actionthrottle closing mechanism effective to accommodate the time lag in thedisengagement of the vacuum controlled clutch when the accelerator pedalis entirely released thereby effectively synchronizing the disengagementof the clutch and the deceleration of the engine and effecting auniformly smooth operation of th vehicle.

Other objects of the invention will appear in the following descriptionand appended claims, reference being had to the accompanying drawingsforming a part of this specification wherein like reference charactersdesignate corresponding parts in the several views.

Fig. 1 is a fragmentary view, partly diagrammatic and in section,illustrating portions of' the carburetor, control mechanism and powerplant.

Fig. 2 is a front elevation of the carburetor.

Fig. 3 is a view similar to Fig. 2 with the float chamber partly insection and certain parts omitted.

Figs. 4 and 5 are views similar to Fig. 3 but showing the parts indifferent positions.

Fig. 6 is a detail section taken substantially on the line B-6, Fig. 2.

Fig. 'I is a detail section taken substantially on the line 1 1, Fig. 3.

Fig. 8 is a perspective view, in part diagrammatic, illustrating thecarburetor and vacuum clutch assembly together with operating mechanismtherefor.

Before explaining in detail the present invention, it is to beunderstood that the invention is not limited in its application to thedetails of construction and arrangement of parts illustrated in theaccompanying drawings, since the invention is capable of otherembodiments and of being practiced or carried out in various ways. Alsoit is to be understood that the phraseology or terminology employedherein is for the purpose of description and not of limitation, and itis not intended to limit the invention claimed herein beyond therequirements of the prior art.

In Fig. 1 there is shown at A a portion of an automobile engine having asuitable number of cylinders I5, pistons I6, valves l1 and spark plugsi8, and an intake manifold i9 supplied with fuel mixture from acarburetor 20 under the control of a throttle valve 2l. 'I'he throttlevalve 2l is carried by a rock shaft 22 having fast thereon an 'arm 23,pivotally connected through a link 26 to one end of a bell crank lever24 pivoted at 24a to the manifold casing. The opposite end of this leverhas an enlarged portion l0 provided with an arcuate slot li ofcalculated length within which is slidingly connected for predeterminedlost motion al pin I4 carried at the forward end of a link or push andpull rod 21. 'Ihe opposite end 21a (see Figs. 1 and 8) of this rod ispivoted to the outer end of an arm 2B fixed at its inner end to a rockshaft Il. This shaft may be rocked through the medium of a conventionalaccelerator pedal 29 pivoted to a bracket secured to the toe-board, thepedal .being connected by means of a link 28 to a second arm l2 ilxed tothe shaft. Suitable return springs 30 and Il are employed to close thethrottle and elevate the accelerator pedal when the latter is releasedby the driver.

The carburetor 20 herein shown (see also Figs. 2 to '1) for purposes ofillustration is, generally speaking,ofawel1knownd1wndrafttypehavingafloatchambern andameteringpinfor controlling the admission of liquidfuel from the oat chamber 32 to the mixing chamber. The metering pin 33is carried by a lever pivoted at 540 to a bracket 34| on the top of thefloat chamber and connected by a link 35 to an arm 55 fast on thethrottle valve stem 22, whereby the metering pin is retracted to openthe fuel supply jet or advanced to close the iet simultaneously with theopening and closing of the 'throttle valve, respectively. 'I'he lever 34is also connected with the plunger 51 of a fuel pump for injecting a.priming or accelerating jet of fuel into the mixing chamber when thethrottle is opened. 'I'he carburetor shown is further provided with a.choke valve controlled by a thermostat located in housing 39 and alsocontrolled from the throttle valve by engagement of a finger 45 cn thelever 34 with an arm 4I on the choke valve shaft 38.

AExcept as hereinafter pointed out, or as they enter into combinationwith the parts hereinafter described, the parts above referred tospecifically constitute no portion of the present invention and may beof any approved construction and arrangement.

In accordance with the present invention, the float chamber 32 hasformed in the bottom thereof a dash pot cylinder 44. This cylinder may,if desired, be constructed separately and threaded into the bottom ofthe oat chamber, but when in place constitutes a unitary part of thefloat chamber and is constantly supplied with liquid v.from the latter.Working in the cylinder 44 is a dash pot plunger '45 in the form of apiston comprising, in the present instance, an inverted cupshaped washer45 carried by a rod 41 drilled to provide suitably restricted ports 45communicating with the interior of the cylinder at opposite sides of thepiston. Upward movement of the piston 45 is limited by shoulders 49provided by a rib formed on the interior of the float chamber. At itsupper end, the rod 41 is connected by a link 50 with the longer arm ofavlever 5| pivoted at 52 to a bracket 53 on the top ofthe float chamber.The shorter arm of the lever 5l is connected by a link 54 with a bellcrank arm 55 pivotally mounted to turn freely on the throttle valveshaft 22 adjacent the arm 55, the arm 55 having a downward extensionconnected with the arm 3G by a spring 56. The arm 34 is formed with astirrup portion 51 non-rotatably mounted on the throttle valve stem 22and held in place by a set screw 58. The arm 55 is provided with a lug59 which| when arms 35 and 55 are in the relative positions shown inFigure 5, is engaged by the top of the stirrup portion 51 of the arm 55.

The position of the parts when the throttle valve is fully closed isshown in Fig. 3. To open the throttle valve and retract the metering pin33, the throttle valve stem 22 is turned in a clockwise direction asviewed in the latter figures, therebyl through the arm 35, link 35, andlever 54 retracting or elevating the metering pin 55. During the initialportion of this opening movement, the ann 55, under the inuence of thespring 55, follows the movement of the arm 35, thereby, through the link54 and lever 5I, raising the dash pot plunger until movement of thepiston 45 is arrested by engagement with the shoulders 49. During thisoperation, the dash pot plunger offers no material resistance to themovement of theparts, since the top of the cylinder 44 is open to theoat chamber 32. When the movement of the dash pot plunger is arrested byeii- Nement of the piston 45 with the shoulders 45, as shown in Fig. 6,the movement of the arm 55 is likewise arrested, and during the furtheropening of the throttle valve the stirrup portion 51 cf the arm 35 movesaway from the lug 55 until the throttle valve has been fully opened asshown in Fig. 5. Thereafter the throttle valve may be opened and closed,and the metering pin advanced and retracted, between the positions shownin Figs. 4 and 5, without interference or modincation of its action bythe dash pot. Certain features of the above-described carburetor arecovered in copending related applications Serial No. 448,197, fliedOctober i3, 1934 and Serial No. 94,191, led August 4, 1936.

When the accelerator pedal is released, the throttle return springs 30and 3l, acting through the links and levers above described and thethrottle arm 23, turn the throttle valve shaft in a counter-clockwisedirection as viewed in Figs. 3, 4 and 5, thereby moving the throttlevalve towards closed position and advancing the metering pin 33downwardly toward the position for maximum restriction of the feed ofthe fuel to the carburetor mixing chamber. During this closing movement,when the parts reach substantially the position shown in Fig. 4, thepart 51 of the arm 38 engages the lug 59 on the arm 55. Movement of arm55 in a counter-clockwise direction is resisted and retarded by the dashpot whose plunger is forced downwardly in the cylinder 44 by suchcounter-clockwise movement of the arm 55. The final closing of thethrottle valve, as well as the movement of the metering pin 33 into itsfully advanced position, is thereby checked and retarded, so that thefuel mixture will continue to be admitted to the engine for a limitedtime in decreasing amounts substantially proportionate to the naturaldeceleration of the car, thus preventing the speed of the latter frombeing abruptly checked.

Referring to Fig. l, when the accelerator pedal is fully raised as shownin said figure the rod 21 will have been moved forwardly (to the rightin said figure) to the limit of its throw, this action beingaccomplished principally through the relatively heavy main or primaryclosing spring 3|. At this point the connection I4 of the rod will lieat the forward end of the slot, the throttle valve will be in its nearlyclosed position shown in Fig. 4, and the actuator part 51 will havereached a position substantially or nearly in engagement with the lug59. Final closing movement of the throttle from this point isaccomplished by the secondary closing spring 35, and it will be seenthat when the rod 21 has thus reached the limit of its forward travel inclosing direction, the bell crank lever will be free to turn further ina closing direction independently of rod 21 and spring 3i. 'Ihis finalrange of closing movement of bell crank 24 (when the accelerator pedal29 has been entirely released by the driver) is produced by tensionspring 30 and is opposed by the dash pot. During this final movement thepart 51 engages lug 59, swings the bell crank lever 55 about its pivot,raises link 54 and through lever 5I and piston rod 41 `forces the dashpot piston downwardly within the cylinder against the resistance of theliquid therein, thus edectively retarding the nal range of closing ofthe throttle between its positions shown in Figs. 4 and 3. During thistime the spring 55 is preferably free of tension. When the throttlevalve has reached its final closed position, see Figs. l

Ya supporting bracket 14.

Referring to Fig. 8 it will be seen that thel accelerator pedal 29 isconnected through the medium of the rock shaft I3 with a vacuum operatedunit connected to mechanism for actuating the clutch. This mechanismcomprises a suitl able cylinder 10 having mounted therein areciprocating vacuum operated piston. A rod 1I is connected to thepiston and is adapted to be reciprocated thereby. This rod is pivoted toa bell crank lever 12 which in turn is pivoted at 13 to A link 15connects the bell crank 12 with a crank arm 16 attached to a clutchoperating rock shaft 11 having the usual clutch throw-out ngers 18. Theclutch unit proper is not shown herein since it m/ay be of anyconventional type. The connections between the accelerator pedal 29 andthe vacuum unit comprise `a crank arm 19 secured to the rock shaft I3, alink 80 connecting this arm with one arm of a bell crank lever 8|pivoted to a fixed bracket 82, and a link or rod 83 connecting the otherarm of the bell crank 8l with a reciprocable plunger valve 84 operablewithin a cylinder 85 having an inlet port communicating through a pipe86 with the intake manifold I9. The cylinder 85 has a port incommunication with the cylinder 1li at one side of its pistonandcontrolled by the plunger valve 84.- Movement of the rod 83 in thedirection of the arrow will shift the valve 84 into position to shut offthe vacuum communication of cylinder 1D with the intake manifold wherebythe clutch will be engaged by the usual clutch return spring. The vacuummechanism for automatically operating the clutch may be renderedineffective by means of a cut-off valve plunger 88a operatingwithin acylinder BB and controlled by a Bowden wire connection 31 to a.'manually adjustable device 88 on the dash. At this time the clutch willbe under the drivers control solely through the clutch pedal S9 andconnections @i between the clutch pedal and a crank arm 92 secured tothe rock shaft 11.

As above stated, when the engine is idling with the throttle valve inits fully closed position the pin i4 will 'occupy an intermediateposition within the slot ii, see Figs. l and 8. When, therefore, theaccelerator pedal 29 is depressed the pin i4 will have a certain idlemovement Within the slot portion y before the bell crank lever 24 ismoved, by the continued depression of the accelerator pedal, to open thethrottle valve. During this idle movement, however, of the pin i4 withinthe slot II, lthe connecting rod 83 and vacuum control valve 84 will beretracted so -as to close or partially 'close communication between theintake manifold and the cylinder 10. Thus, the initial opening of thethrottle valve by depressing the accelerator pedal is delayed during apredetermined interval of time to permit independent closing movement ofthe vacuum control valve 84. It has been found that a certain time lagoccurs in the engagement of the clutch by the clutch return spring, andthis time lag is accommodated by providing the delayed opening of thethrottle valve when the accelerator pedal is depressed. This delayedaction, however, is not sufficient to prevent the throttle valve openingin time to cause the engine to accelerate and its speed to equal orexceedV the car speed to the desired degree when the clutch becomesengaged. From the foregoing it will, therefore, be seen that a lostmotion of the actuating rod 21 occurs when the accelerator pedal isinitially depressed, permitting an initial independent movement of thevacuum control valve 84 before the throttle valve opens, therebyoffsetting the time lag in the vacuum cutting-out within the cylinder 10preparatory to engagement of the clutch by the clutch return springs.

It will also be seen that the dash pot retarding device as well as thelost motion connection I4, I I performs an important function incooperation with the automatic vacuum controlled clutch mechanism forproducing a properly timed disengagement of the clutch duringdeceleration of the engine when the accelerator pedal is released. Ithas been found that when the control valve 85 is shifted, upon releaseof the pedal 29 to open vacuum communication between the cylinder 10 andintake manifold a certain time lag or delay occurs in the vacuumbecoming 'effective to retract the piston within the cylinder 1U andthereby to disengage the clutch (against the resistance of its returnsprings) through the mechanism 1I-18. -This time lag has resultedfrequently in undesirably delaying the clutch disengagement upon rapidengine deceleration resulting often in noticeable jerks and backlashwhich are objectionable to the passengers. In order to overcome thesedisadvantages I have provided means whereby the vacuum control valvewill be opened and the clutch disengaged before the throttle valve hasfinally closed and before there has occurred during deceleration such achange in torque conditions as to produce the above mentionedobjectional effects. These improvements in operation have preferablybeen accomplished, by virtue of the present invention, first, byimparting to the throttle valve a final range of closing movement afterthe vacuum control valve has completed its opening movement, and,second, by retarding this ilnal closing movement of the throttle, thusoffsetting the time lag in the vacuum mechanism becoming effective todisengage the clutch. As a result, the clutch will disengage before anapproximate point has been reached during the deceleration-.of theengine where the car tends to drive the engine. From the foregoing,therefore, it will be seen that no undesirable delay in the clutchdisengagement occurs when the accelerator pedal is suddenly released andthe engine decelerated.

I claim:lv

i. In combination, a carburetor having a throttle valve, a vacuumcontrolled device for actuating a clutch, mechanism for controlling saiddevice, Joint control means for said valve and said mechanism, and meanswhereby the last part of the closing movement of said throttle valve iseffected independently of said control mechanism after completion of themovement of said joint control means in a direction to close saidthrottle valve.

2. The combinationvof a carburetor having a throttle valve, vacuumcontrolled mechanism for actuating a clutch, an accelerator pedal, avacuum control valve for controlling said mechanism,

means for moving said control valve from said pedal, means for movingsaid throttle valve from said pedal, and means whereby closing movementof said throttle valve may be continued independently of said controlvalve after completion of the movement of said accelerator pedal in adirection to close said throttle valve.

3. In combination. a carburetor having a throttle valve. an acceleratorpedal, a device connected to said valve for moving the same towardclosed position, mechanism connected to said pedal and having a lostmotion connection with said device for actuating the same, retardingmeans adapted to affect the throttle valve only during a nal range oi'closing movement thereof for retarding such closing movement, saiddevice being free to move said valve independently of said mechanismduring such iinal range of closing movement. a vacuum control valve forcontrolling a vacuum operated clutch mechanism, and means connectingsaid mechanism to said control valve whereby said iinal range of closingmovement of said throttle is eilected independently of said controlvalve.

4. In combination, a carburetor having a throttle valve, an acceleratorpedal, a device for moving said valve toward closed position, mechanismconnected to said pedal and having a lost motion connection with saidthrottle valve for actuating the same, a dash pot having a cylindercommunicating with the carburetor float chamvber and a piston adapted toailect said throttle valve only during a final range of closing movementthereof for retarding such closing movement, said device being free tomove said valve independently of said mechanism during said final rangeof closing movement, a vacuum control valve for controlling a vacuumoperated clutch mechanism, and means connecting said mechanism to saidcontrol valve whereby final range of closing movement of said throttlevalve is effected independently of said control valve.

5. In combination, a carburetor having a throttle valve for controllingthe flow of fuel mixture to an engine, an accelerator pedal, a movablevacuum control valve for an automatic vacuum controlled clutch operatingmechanism, and means connected to said pedal and to said valves forsimultaneously moving the same upon moving the pedal, the connectionbetween said valves including a lost motion device whereby an initialmovement of said pedal in the direction for opening said throttlead'ects said control valve independently of said throttle and a finalmovement of said throttle in the closing direction is eii'ectedindependently of said control valve.

6. 'I'he combination in a carburetor of a throttle valve for controllingthe iiow of fuel mixture to an engine, an accelerator pedal, a movablevacuum control valve for an automatic vacuum controlled clutch operatingmechanism, a common means connected to said pedal and to said valves forsimultaneously moving the same upon moving the pedal, and mechanismwhereby movement is imparted to the control valve independently of andin advance of the movement oi' the throttle valve when the pedal isinitially moved to accelerate the engine and also ywhereby a iinalclosing movement is imparted to the throttle valve independently of andafter ilnal movement of the control valve during the deceleration of theengine.

7. In combination. a carburetor having a throttle valve for controllingthe ilow of fuel mixture to an engine, an accelerator pedal. a movablevacuum control valve i'or an automatic vacuum controlled clutchoperating mechanism. means connected to said pedal and to said valvesfor simultaneously moving the same upon movement of said pedal.mechanism whereby movement is imparted to said control valveindependently of and in advance of the movement of the throttle valvewhen the pedal is initially moved to accelerate the engine and alsowhereby a final closing movement is imparted to the throttle valveindependently of and after ilnal movement of the control valve duringthe deceleration oi' the engine, and a dash pot device for retardingsaid nnal closing movement of the throttle valve.

8. In combination, a carburetor having a throttle valve for controllingthe iiow of fuel mixture to an engine. an accelerator pedal, a movablevacuum control valve for an automatic vacuum controlled clutch operatingmechanism, means connecting to said pedal and to said valves forsimultaneously moving said valves upon movement of said pedal, meanswhereby a ilnal range of closing movement is imparted to said throttlevalve independently oi' said connecting means and after ilnal movementof said control valve, and means for retarding said throttle valveduring said' ilnal range of closing movement.

RALPHH.

